Lamp socket



March 28, 1939. E. E, FOLSOM LAMP SOCKET 'Fil ed Oct. 12, 1938 Inventor: Elwood E. Folsom,

His Attorneg.

Patented Mar. 28, 1939 UNITED STATES PATENT OFFICE 'LABIP SOCKET New York Application October 12, 1938, Serial No. 234,657

6 Claims.

This invention relates to a lamp socket, and more particularly to a socket for a lamp having prong contacts such as a sodium vapor lamp.

It is an object of the invention to provide an i improved form of lamp socket of the type described having relatively few parts which may be easily assembled and manufactured at low cost.

In the accompanying drawing Fig. 1 shows the socket in elevation; Fig. 2 is a sectional view through the socket along the line 22 of Fig. 1,

and Fig. 3 is an exploded view of the socket elements.

Referring to the drawing, the socket housing is shown as comprising a base I!) and a cooperating cover H which are formed of insulating material such as a molded phenolic condensation product. The housing receives a plurality of contact members i2 which are of a form adapted to receive the prongs of a lamp, such as 30 a sodium vapor lamp. All of the contact elements are identical so that one only will be described with particular reference to the showing of Figs. 2 and 3.

In the form of the invention shown the con- 35 tact I2 is formed of a strip of spring bronze [3 which is bent back upon itself, as shown at M, to form two spaced contact blades l5 and I6. To facilitate entry of a prong connector between the contact blades, the ends of the blades are 30 flared, as shown at H. Each of the blades is lanced, as shown at 3, to provide a tongue l9 which is bent inwardly so that it frictionally engages a prong connector when inserted between the blades. The tongues maintain line contact 5 with the connector prongs and thereby provide an adequate electric connection at all times,

Separation of the contact blades is prevented by means of a screw 25? which passes through each of the blades and is threaded through the rear portion of one of the blades, for example, the

blade Hi. In addition to holding the blades together, the screw 20 provides a terminal means for receiving the bared end of a conducting wire. Lugs are struck up from the blade I3 on each e5 side of the head of the screw to serve as a positioning means for the bared end of the wire. Each of the contacts [2 is loosely mounted within the housing in a manner now to be described.

The base member Iii is provided with a plu- 31! rality of recesses 22 which receive the contact members 52 and hold them loosely within the confines of the base. A corresponding set of recesses 23 is formed in the cover 1 l and the blade portions of the contacts are housed within the --55 confines of the cover as shown most clearly by Fig. 2. In the front of the cover the recesses 23 are pierced to provide prong receiving openings 23' so that connector prongs may be inserted through these openings for insertion between the contact blades. As the connector prongs are inserted within the contact blades, the contacts are supported by the bottoms of the recesses 22 so that considerable pressure may be applied to the socket in attaching it to the prongs of a lamp. It should be noted that this construction permits 10 each of the contacts l2 to float freely within the corresponding recesses 22 and 23, so that the contact may adjust its position to compensate for irregularities in the spacing of the connector prongs of the lamp due to tolerances in manufac- 5 ture, while at the same time the recesses confine the contacts closely enough so that the lamp is mounted securely upon the socket.

The recesses 22 are arranged in pairs at angles to each other so that the contact members may 20 be grouped over an area of minimum diameter to accommodate the prongs of the lamp. Moreover, the arrangement is such that the conductors of the electric cord may be positioned within the housing in a manner to separate the individual 25 conductors and insulate them one from the other. To this end the upper recesses 22, as shown by Figs. 2 and 3, are placed in spaced parallel relationship and are separated by a baffle 24. The bafile 24 is provided with grooves 25 to receive the ends of the screws 28 when the contacts l2 are positioned within the recesses. At one end the recesses 22 extend at an angle to each other, as shown at 22', and are joined together to form a channel 26 for receiving the conductors which are to be attached to the upper contacts. The lower recesses 22 are disposed at an angle to the upper recesses and at an angle to'each other, on each side of the channel 26, and are likewise provided with grooves 2'! to receive the ends of the screws 40 2|] in the lower contacts l2 which are positioned within the recesses. The lower recesses 22 merge to form a second channel 28 which is in alinement with the channel 26. The channel 28 is of sufficient diameter to accommodate the conductors passing to all of the groups of contacts, whereas the channel 26 accommodates the conductors passing to the upper contacts only and is smaller in diameter than the channel 28. By this arrangement the contacts are grouped within an 5 area of minimum diameter and the conductors connected to the respective contacts are segregated one from the other and are closely confined within the housing within the passages 26 and 28 and the respective recesses 22. Looking at the cover ll it will be seen that the upper recesses 23 are disposed in parallel relationship to each other similar to the upper recesses 22, in the base l0, and that the lower recesses are disposed at an angle to each other complementary to the angularly disposed recesses 23. In this way the contacts are positioned accurately in their respective recesses. I

To provide, in effect, a strain relief for the electrical conductor the base l0 and the cover II are provided with complementary extensions 29 extending beyond the confines of the base and which are adapted to surround and grip a conductor which is connected to thesocket in order to prevent any stress or pulls on the conductor from reaching the connections joining the wires of the conductor and contacts. The extension of the cover 29 is provided with a'groove 30 which cooperates with the channel 28 in the base extension for receiving the conductor. The two parts of the housing are secured together by means of screws 3| which pass through openings 32 in the base l0 and arethreaded into inserts 33 molded into the cover member II. In order to receive the base. of the lamp and position it accurately upon the socket the face of the cover member adjacent the openings 23 is provided with a plurality of plain bearing surfaces such as a central bearing surface 34 and an outer concentric bearing surface 35.

By the construction described it is possible to provide a lamp socket having relatively few parts which may be assembled at low cost. All of the contacts are identical and are positioned loosely Within the recesses formed in the housing without the necessity of providing means for securing them to the housing structure. The two parts of the housing are easily molded and are assembled about the contact elements by threading down on the screws 3|. In attaching a conductor tothe socket the bared ends of the conductor wires are first attached to the respective contacts by means of the screws 20, the conductors are then placed within the channels 26 and 28, and the contacts placed within their respective recesses thereby providing a construction which is easily assembled and which is of a compact form. The two parts of. the housing are then secured together around the attached contacts in the manner described. The parts of the housing are formed of cold molded insulating material capable of withstanding the intense heat incident to operation of a lamp such as is the case when a sodium vapor lamp is mounted upon the socket. Moreover, due to the fact that the contacts are mounted loosely within the recesses of the housing, the heat from the lamp prongs and contacts is not transferred readily to the housing material. The thickness of the walls of the housing is such that a socket of rugged construction is formed capable of withstanding rough usage.

' What I claim as new and desire to secure by Letters Patent of the United States, is: 1. In a lamp socket, a housing having two recesses extending angularly toward each other at one end and joining to form a channel, said housing having two other recesses disposed at an angle to each other, one being on each side of said channel and extending toward the other at one end and joining to form a second channel in alinement with said first-mentioned channel, contact members mounted in each of said recesses, and means on each of said contact members for making a connection with electric conductors, the conductors resting in said channels.

2. In a lamp socket, a base having a plurality of recesses therein, two of said recesses extending:

toward each other and forming a channel, other recesses disposed at an angle to each other on each side of said channel, a cover having a plu-- rality of recesses in alinement with the recesses in said base, and contact elements having terminal portions and spaced contact blades for engaging the connector prongs of a lamp, the terminal portions of said contacts being mounted loosely Within the recesses in said base and the blades of said contacts extending into the recesses in said cover whereby said contacts are completely enclosed within said base and cover, the recesses in said cover being provided with openings for insertion of the connector prongs of a lamp intoengagement with said contact blades.

3. In a lamp socket, a housing of substantially circular configuration and provided with an opening for receiving conductors, said housing being provided with two pairs of recesses, 'one of said pairs of recesses being disposed in parallel relationship and merging together to form a channel in alinement with said opening, the recesses of the other pair being disposed at an angle to each other on each side of said channel and merging with said opening, contact members positioned in each of said recesses and conductors connected to each of said contact members and passing through said opening and said channel.

4. In a lamp socket, a housing having two re"- cesses disposed in parallel relationship to each other and extending angularly toward each other at one end and joining to form a channel, said housing having two other recesses disposed at an angle to each other and to said first-mentioned recess, one being on each side of said channel and extending toward the other at one end and joining to form a second channel larger than said firstmentioned channel and in axial alinement therewith, contact members mounted in each of said recesses, and means on each of said contact members for making a connection with an electric conductor, the conductors connected to said firstmentioned two contacts resting in said first-mentioned channel and the conductors connected to all of said contacts resting in said second-mentioned channel.

5. In a lamp socket, a base having two recesses therein extending angularly toward each other at one end and joining to form a channel, said base having two other recesses disposed at an angle to each other on each side of said channel and extending toward each other at one end and joining to form a second channel in axial alinement with said first-mentioned channel, contact members mounted loosely in each of said recesses, said contact members having opposed blade portions adapted to receive the connector prongs of a lamp, means on each of said contact members for making a connection with a conductor, the conductors connected to said first-mentioned two contacts resting in said first-mentioned channel and the conductors connected to all of said contacts resting in said second-mentioned channel, and a cover having recesses in alinement with the recesses in said base for enclosing said contacts.

6. A lamp socket comprising a base having a plurality of recesses therein, two of said recesses being disposed within spaced parallel relationship to each other and being separated by a baffle member, each of said two recesses having a groove formed in said baffle member, said two recesses extending angularly toward each other at one end and joining to form a channel, two more of said recesses being disposed at an angle to each other and to said first-mentioned parallel recesses on each side of said channel and being provided with grooves, said angularly disposed recesses extending toward each other at one end and joining to form a second channel in axial alinement with said first-mentioned channel, contact members having spaced blades mounted loosely in each of said recesses for receiving the connector prongs of a lamp, a terminal screw secured to each of said contact members and extending into its respective groove, said screws being adapted to connect conductors to said contact elements with the conductors resting in said channels, a cover having recesses in alinement with said base for enclosing said contacts, and means securing said base and cover together.

ELWOOD E. FOLSOM. 

